Method for charging gas into cassette pod

Abstract

A method for transporting a cassette pod for containing semiconductor waters is provided. The method includes transporting a cassette pod configured to receive a semiconductor wafer with a transporting apparatus. The method further includes supplying a gas from a cylinder into a housing of the cassette pod. The cylinder is externally positioned on the housing. The method also includes detecting a gas pressure in the cylinder with a detection element. In addition, the method includes issuing a signal to the transporting apparatus when the gas pressure in the cylinder is lower than a predetermined limit.

What is claimed is: 
     
       1. A method for transporting a cassette pod for containing semiconductor wafers, comprising:
 transporting a cassette pod configured to receive a semiconductor wafer with a transporting apparatus; 
 supplying a gas from a cylinder into a housing of the cassette pod, wherein the cylinder is externally positioned on the housing; 
 detecting a gas pressure in the cylinder with a detection element; and 
 issuing a signal to the transporting apparatus when the gas pressure in the cylinder is lower a redetermined limit. 
 
     
     
       2. The method as claimed in  claim 1 , further comprising:
 delivering the gas from the cylinder to the housing via a tube externally positioned on the housing; and 
 controlling a flow of the gas from the cylinder to the housing with a flow control valve connected to the tube. 
 
     
     
       3. The method as claimed in  claim 1  wherein the gas comprises nitrogen gas. 
     
     
       4. The method as claimed in  claim 1 , further comprising
 processing the semiconductor wafer with a processing apparatus, wherein the cassette pod is transported from the processing apparatus to a predetermined destination. 
 
     
     
       5. The method as claimed in  claim 4 , wherein the gas is supplied to the housing prior to the cassette pod is removed from the processing apparatus. 
     
     
       6. The method as claimed in  claim 4 , wherein the gas is supplied to the housing no later than the cassette pod is removed from the processing apparatus. 
     
     
       7. The method as claimed in  claim 4 , wherein the predetermined destination comprises a stocker, and the method further comprises storing the cassette pod in the stocker. 
     
     
       8. The method as claimed in  claim 4 , wherein the predetermined destination comprises another processing apparatus, and the method further comprises processing the semiconductor wafer with the another processing apparatus. 
     
     
       9. The method as claimed in  claim 1 , further comprising replacing the cylinder with another cylinder filled with the gas when the signal is issued. 
     
     
       10. The method as claimed in  claim 1 , further comprising:
 transporting the cassette pod to a work station when the signal is issued; and 
 removing the semiconductor wafer to another cassette pod which is equipped with another cylinder filled with the gas. 
 
     
     
       11. The method as claimed in  claim 1 , further comprising:
 closing a door after the at least one semiconductor wafer is loaded into the housing to form an enclosure and issuing a request to initiate the charging of the gas simultaneously. 
 
     
     
       12. A method for transporting a cassette pod for containing semiconductor wafers, comprising:
 processing a semiconductor wafer with a processing apparatus; 
 placing the semiconductor wafer processed by the processing apparatus into a housing of a cassette pod; 
 supplying a gas from a cylinder into the housing, wherein the cylinder is externally positioned on the housing; 
 detecting a gas pressure in the cylinder with a detection element; and 
 moving the cassette pod to a work station to replace the cylinder with another cylinder filled with the gas in response to a signal issued by the detection element when the gas pressure in the cylinder is lower than a predetermined limit. 
 
     
     
       13. The method as claimed in  claim 12 , further comprising:
 delivering the gas from the cylinder to the housing via a tube externally positioned on the housing; and 
 controlling a flow of the gas front the cylinder to the housing with a flow control valve connected to the tube. 
 
     
     
       14. The method as claimed in  claim 12 , wherein the gas comprises nitrogen gas. 
     
     
       15. The method as claimed in  claim 12 , further comprising transporting the cassette pod from the processing apparatus to a predetermined destination when the signal is not issued,
 wherein the gas is supplied to the housing prior to the cassette pod is removed from the processing apparatus. 
 
     
     
       16. The method as claimed in  claim 12 , further comprising transporting the cassette pod from the processing apparatus to a predetermined destination when the signal is not issued;
 wherein the gas is supplied to the housing no later than the cassette pod is removed from the processing apparatus. 
 
     
     
       17. The method as claimed in  claim 12 , further comprising:
 closing a door after the processed semiconductor wafer is loaded into the housing to form an enclosure and issuing a request to initiate the supply of the gas simultaneously. 
 
     
     
       18. A method for transporting a cassette pod for containing semiconductor wafers, comprising:
 placing a housing of a cassette pod on a gas purging assembly, wherein a gas inlet of the housing is connected to a gas spreading member of the gas purging assembly, and a gas is discharged from the gas purging assembly into the housing via the gas spreading member and the gas inlet; and 
 removing the housing from the gas purging assembly and mounting a cylinder to an outer surface of a side fixed wall of the housing, wherein a tube is disposed outside of the housing and connects the cylinder to the gas inlet, and another gas is discharged from the cylinder into the housing via the tube and the gas inlet. 
 
     
     
       19. The method as claimed in  claim 18 , further comprising:
 transporting the cassette pod with a transporting apparatus while the gas is discharged from the cylinder into the housing; and 
 detecting a gas pressure in the cylinder with a detection element; 
 wherein the transporting apparatus moves the cassette pod to a work station to replace the cylinder in response to a signal issued by the detection element when the gas pressure in the cylinder mounted on the housing is lower than a predetermined limit. 
 
     
     
       20. The method as claimed in  claim 18 , wherein the gas comprises nitrogen gas.